Clinical findings from a large endo-epicardial atrial arrhythmia ablation registry

Abstract Background Despite advances, catheter ablation success rates for persistent AF remain at 50-60%. The approach for recurrent persistent AF, beyond pulmonary vein isolation, remains contentious. Surgical maze procedures have demonstrated superior outcomes compared to catheter ablation. Catheter-based linear lesions sets have failed to demonstrate efficacy, perhaps due to a lack of consistent transmurality with endocardial radiofrequency. Objective We report our safety and clinical data of an endo-epicardial approach using high-power radiofrequency ablation for atrial arrhythmias. Methods 183 patients (79% male; mean age 66 years [21-85]) underwent ablation, between August 2020 and July 2024, for symptomatic atrial arrhythmias using an endo-epicardial approach. We used a standardised linear lesion set (posterior wall isolation and anterior mitral line) for recurrent persistent AF and left sided AT. Results Utilising an intentional coronary sinus exit and C02 insufflation technique, we achieved epicardial access in 178 anticoagulated patients. 5 patients were found to have pericardial adhesions, prohibiting access. There were 2 LIMA punctures which were coiled, 3 cases of excess pericardial bleeding (not access related), that settled conservatively, and no patients requiring surgery or death. 92% of patients received epicardial ablation. 126 anterior mitral lines (96% acute block, 85% with epicardial ablation), 128 roof lines (88% blocked, 61% with epicardial ablation) and 123 floor lines (98% blocked, 47% with epicardial ablation) were undertaken. 117 posterior wall isolations were performed (88% isolated, 56% epi ablation). 85 patients had a standardised lesion set and were included for recurrence analysis. 65 had persistent AF (71% male, mean age 65.4 years, mean LAVI 37.4 ml/m2) and 33 long-standing persistent AF (88% male, median age 64 years, mean LAVI 38.3 mls/m2). 92% with persistent AF (median follow up time 13.3 months) and 61% with longstanding persistent AF (median follow up time 16.5 months) maintained freedom from persistent AF/left sided AT. Conclusion In one the largest cohorts to date, we have shown that endo-epicardial atrial ablation is feasible and safe with epicardial ablation allowing improved transmurality and thus acute linear block. Clinical outcomes, using a posterior wall isolation and anterior mitral line, were favourable for persistent but not long-standing persistent AF.